Acceptable outcome following resection of bilateral large popliteal space heterotopic ossification masses in a spinal cord injured patient: a case report

Spinal cord injury is a well-known predisposing factor for development of heterotopic ossification around the joints especially hip and elbow. Heterotopic ossification about the knee is usually located medially, laterally or anteriorly; besides, the knee is generally fixed in flexion. There are only a few reports of heterotopic bone formation at the posterior aspect of the knee (popliteal space) and fixation of both knees in extension; so, there is little experience in operative management of such a problem

Real-time reversible tunable elasticity in cellular solids via electromagnetic actuation

The ability for reversible, real-time control of elastic moduli in solids can find significant application in advanced mechanical components, protective structures, and biomedical devices. Here, we propose a novel concept for controlling the linear and nonlinear elastic properties of cellular structures via electromagnetically triggered mechanisms in the cellular solid. Three structural systems with orthotropic material properties were proposed and studied numerically, experimentally, and analytically. Using the proposed concept, the elastic modulus can be controlled over two to four orders of magnitude. The Poisson ratio of the isotropic structure can be varied from 0 to 0.5 continuously. The adjustments over nonlinear elastic (i.e., buckling) behavior of the structure are achieved by activation of supplementary cell walls in the lattice through electromagnetic actuation. Magnetic actuation will hamper the first symmetrical buckling pattern of the structure and force the structure to buckle according to a higher buckling pattern with smaller sinusoidal wavelength in the cell walls. The uniaxial buckling strength of the structure was tuned over two orders of magnitude

Modeling the effect of levothyroxine therapy on bone mass density in postmenopausal women: a different approach leads to new inference

<p>Abstract</p> <p>Background</p> <p>The diagnosis, treatment and prevention of osteoporosis is a national health emergency. Osteoporosis quietly progresses without symptoms until late stage complications occur. Older patients are more commonly at risk of fractures due to osteoporosis. The fracture risk increases when suppressive doses of levothyroxine are administered especially in postmenopausal women. The question is; "When should bone mass density be tested in postmenopausal women after the initiation of suppressive levothyroxine therapy?". Standard guidelines for the prevention of osteoporosis suggest that follow-up be done in 1 to 2 years. We were interested in predicting the level of bone mass density in postmenopausal women after the initiation of suppressive levothyroxine therapy with a novel approach.</p> <p>Methods</p> <p>The study used data from the literature on the influence of exogenous thyroid hormones on bone mass density. Four cubic polynomial equations were obtained by curve fitting for Ward's triangle, trochanter, spine and femoral neck. The behaviors of the models were investigated by statistical and mathematical analyses.</p> <p>Results</p> <p>There are four points of inflexion on the graphs of the first derivatives of the equations with respect to time at about 6, 5, 7 and 5 months. In other words, there is a maximum speed of bone loss around the 6^thmonth after the start of suppressive L-thyroxine therapy in post-menopausal women.</p> <p>Conclusion</p> <p>It seems reasonable to check bone mass density at the 6^thmonth of therapy. More research is needed to explain the cause and to confirm the clinical application of this phenomenon for osteoporosis, but such an approach can be used as a guide to future experimentation. The investigation of change over time may lead to more sophisticated decision making in a wide variety of clinical problems.</p

SpiderWeb honeycombs

A new class of hierarchical fractal-like honeycombs inspired by the topology of the “spiderweb” were introduced and their small and large deformations were investigated analytically, numerically, and experimentally. Small deformation elasticity results show that the isotropic in-plane elastic moduli (Young’s modulus and Poisson’s ratio) of the structures can be controlled over several orders of magnitude by tuning dimension ratios in the hierarchical pattern of spiderweb, and the response can vary from bending to stretching dominated. In large deformations, spiderweb hierarchy postpones the onset of instability compared to stretching dominated triangular honeycomb (which is indeed a special case of the proposed spiderweb honeycomb) and exhibits hardening behavior due to geometrical nonlinearity. Furthermore, simple geometrical arguments were obtained for large deformation effective Poisson’s ratio of first-order spiderweb honeycombs, which show good agreement with numerical and experimental results. Spiderweb honeycombs exhibit auxetic behavior depending on the nondimensional geometrical ratio of spiderweb

Clinical and histological features of nonalcoholic steatohepatitis in Iranian patients

BACKGROUND: Although several studies have been performed on risk factors and natural course of NASH, it seems that NASH tends to be more than a disease confined to strict boundaries. The objective of this study was to assess the clinical and paraclinical features and risk factors for non-alcoholic steatohepatitis (NASH) patients in an Iranian population METHODS: Patients with histologically confirmed NASH who had elevated liver aminotransaminases, negative serologic markers of viral or autoimmune hepatitis and no findings in favor of metabolic liver disease were enrolled. A careful history was taken regarding alcohol intake. RESULTS: 53 patients consisting of 32 male and 21 female entered the study. The mean age was 37.8 ± 11.3 years. Twenty-six patients (55.3%) were overweight, 15 (31.9%) obese, 40 (75.5%) dyslipidemic, and three patients (5.7%) were diabetic. Liver biopsy showed mild steatosis in 35.7%, moderate steatosis in 53.6%, and severe forms in 10.7%. In 80.2% of patients, portal inflammation was present, and 9.4% had cirrhosis. The amount of increase in liver enzymes bore no relationship with fibrosis, portal inflammation, and degree of steatosis. CONCLUSIONS: The patients in our study showed a male predominancy and were somewhat younger than other studies

Blended learning for teacher professional learning

Lärare behöver professionellt lärande för att skolresultaten ska förbättras. För att det ska göra skillnad för alla elever så behöver alla lärare delta i den. Samtidigt visas en brist på organiserat professionellt lärande för lärare (Skolverket, 2013). Digitaliseringen skapar nya möjligheter. Lärande online kännetecknas av att vara flexibel tids- och rumsmässigt. Något som kan möta det tidsmässiga hinder som skolledare uttrycker (Skolinspektionen, 2015). Forskning, av Means et al. (2009), visar att lärande med blended learning; där undervisning och lärande i det fysiska rummet kombineras med undervisning och lärande online, ger bättre effekt än lärande helt fysiskt respektive helt online. Denna studie har tittat på hur de olika undervisningsmiljöerna i blended learning; fysiskt respektive online, kan tillämpas för att skapa förutsättningar för ett framgångsrikt professionellt lärande. Metoden metasyntes har använts för att sätta samman resultat från olika studier i syfte att skapa en samling vetenskapligt grundade råd; en best practice att luta sig på vid framtida planering. Studien är teoretiskt influerad av ett sociokulturellt perspektiv på lärande. Metasyntesen visar att blended learning kan vara en god form att tillämpa. Det är tydligt att de båda undervisningsmiljöerna; fysiskt och online, är viktiga. Vid de fysiska träffarna vårdas och stärks sociala relationer, medan onlinemiljön erbjuder en betydelsefull tids- och rumsmässig flexibilitet. Förutsättningar för ett framgångsrikt professionellt lärande med blended learning är att strukturella resurser som god IT-miljö och avsatt tid för lärandet finns. Metasyntesen är tänkt som ett stöd för skolledare och andra beslutsfattare inför planering av framtida professionellt lärande för grundskollärare.Teachers need professional learning opportunities to improve school results. To have impact for all students, all teachers need to participate. However, there is currently an acknowledged lack of organized professional learning for teachers (Skolverket, 2013). Technology creates new possibilities. Online learning is known to be flexible in terms of time and space, a feature that can help meet the time-related obstacles that school leaders report (Skolinspektionen, 2015). Research, by Means et al. (2009), shows that blended learning, a method where teaching and learning face-to-face is combined with teaching and learning online, has a better effect then exclusively face-to-face or online approaches. This study has explored how the different teaching environments in a blended learning approach; face-to-face and online, can be used to create successful professional learning opportunities. The method used is research synthesis to combine results from different studies in order to create an overarching account of best practice to draw on during future planning. The study is theoretical influenced by a sociocultural view of learning. The research synthesis shows that blended learning can be a promising approach. It is clear that both the teaching environments; face-to-face and online, are important. It shows that social relationships are particularly strengthened by face-to-face meetings, while online solutions offer increased flexibility in terms of time and space. The results also show that necessary conditions for successful blended learning initiatives include structural resources such as good ICT and allocated time for learning. This research synthesis is intended to support school leaders and policymakers in the planning of future teacher professional learning

Anatomical, physical and chemical properties of Sepestan wood (Cordia myxa L.) in Iranshahr region

Cordia (Sepestan in Persian) species (Cordia myxa L.) is in the borage family (Boraginaceae) and it is growing with geographical distribution in the moderate and tropical regions of Iran such as near the Persian Gulf, especiallyin Bandar Abbas and some places in Kerman and Sistan and Baluchestan region but its anatomical characteristics have not been studied yet. In this study, some of the anatomical, chemical and physical properties of Sepestan wood in Iranshahr region in Sistan and Baluchestan Province were measured. Anatomical studies showed that this species has average diameter vessels, simple vascular perforation plate and intervessel pits alternate. Its ray xylems type is heterogeneous and contains abundant crystals. The wood tissue is parenchyma with abundant prismatic crystals and in the cross-section parenchyma was observed in gregarious and continuous formation. Average length, overall diameter, lumen diameter and wall thickness of the fibers were measured 1329, 33.5, 21.7 and 5.9 microns respectively. Also investigation of chemical characteristics showed that Sepestan wood has average cellulose 34.75, lignin 20.6, extractives soluble in acetone 7.88 and also 8.9 percent ash. The results also showed that the specific gravity of the wood is 0.4 and maximum volumetric swelling and shrinkage were 10.98 and 12.34 percent respectively

Comparative on the Microscopic Properties of wood near the pith to bark in Dalbergia sissoo in ShoshDanial

In this research microscopic properties of wood near the pith to bark in Dalbergia sissoo was investigated. For this reason 3 stands of 10 years old Dalbergia sissoo trees from ShoshDanial area in Khozestan province were selected and cut. For measuring fiber biometrics of samples, from each trees one disc and from each disc 10 pell in match's size segregated and tested. Segregation of fibers was done with Franklin method. Also microscopic segments of wood near the pith and bark were studied with light microscope. The results showed that the length, total and lumen diameter, and thickness of cell wall are significantly different and this values were increased from pith to bark. Ray widths and vessel diameters in wood near the pith and bark were 36.15, 132.98 and 31.82, 98.26 µm respectively and showed a significant difference in the level of 5%. The average number of vessels and the number of rays in wood near the pith and bark were 3.46, 7.20 and 3.54, 6.68 number respectively. Also ray length means in wood near the pith and bark were 130.86 and 132.05µm respectively and didn’t show a significant difference in the level of 5%